Does anyone have a GPS to find my fortune? Net worth down $2.9 billion in past 12 months as shares of Global Positioning System outfit Garmin down 64% since January. Met partner Gary Burrell at AlliedSignal. Produced Global Positioning System navigation tools for pilots and sailors. Started marketing GPS units to directionally challenged drivers in 1998; demand for navigation technology flourished last year. Sales up 28% to $1.6 billion in first half of 2008.